Record and Guide, a driveway led from 92nd Street to this frontispiece. From ground level to the top of the second floor, the center of the original Fifth Avenue elevation projects slightly, with balconies on the second and third floors. There are rectangular windows elsewhere on the ground floor, as well as a service entrance on 92nd Street. The fourth floor is recessed at the center and right of the 92nd Street façade. The roofline of the 92nd Street façade is also recessed at its center. The museum's annex, designed by Kevin Roche, imitates the original mansion's style. The façade of the annex on Fifth Avenue measures wide and is recessed from that of the older structure. Interior After entering from 92nd Street, visitors originally passed through a vestibule with an ornamental metal-and-glass screen and door. There was a grand pipe organ at the rear of the house. Adjacent to the organ, a staircase led to the upper floors. A dumbwaiter in the rear also connected the bedrooms upstairs with the main pantry and serving room downstairs. The fourth floor contained the bedrooms of Warburg's son and daughter, and a study was placed in the corner of that story, directly above the sitting room. The eastern end of the fourth story contained a nursery, as well as a bedroom for the child and nurse. On the fifth floor, there were guests' bedrooms with bathrooms on the western end, as well as a squash court, tea room, and shower with toilet on the eastern end. An electric elevator connected all stories between the basement and the sixth floor. The Jewish Museum's annex, completed in 1993, contains an auditorium with architectural elements preserved from the mansion. These include a partition screen that was once installed near one of the mansion's staircases, as well as a dome made of stained glass. Other spaces in the annex include design elements, such as columns and moldings, which are similar to the design details in the original building. The annex also contains exhibition galleries, a bookstore, museum offices, and a reception hall. The upper stories contain more offices, as well as a library, study area, and meeting rooms. The furnishings were provided by Ralph Appelbaum Associates. Critical reception In 1909, after the Warburg Mansion was completed, the Real Estate Record and Guide described the building as one of "a number of palatial residences" along Fifth Avenue.